* Fuel injection systems are sophisticated: Modern fuel injection systems precisely meter fuel based on various sensor inputs (airflow, temperature, engine speed, etc.). Holding the gas pedal down overrides this system, flooding the engine with too much fuel.
* Purpose of the gas pedal during starting: The gas pedal's only role during starting is in *very* old, carburetor-equipped vehicles where it might be necessary to provide a slightly richer mixture for cold starting. Even then, it wouldn't require holding it down.
* Possible causes of needing to hold the gas: If you find yourself in this situation, it indicates a serious underlying issue, such as:
* Faulty Crankshaft Position Sensor (CKP): This sensor tells the engine's computer the position of the crankshaft, crucial for timing fuel injection. A bad CKP can lead to improper fuel delivery, potentially requiring you to manually add more fuel (though it's a very dangerous workaround).
* Faulty Throttle Position Sensor (TPS): A malfunctioning TPS might provide incorrect information to the engine control unit (ECU), disrupting the fuel/air mixture.
* Problems with the ECU itself: The ECU might be malfunctioning and failing to deliver the correct fuel signal.
* Low fuel pressure: Insufficient fuel pressure could mean the engine isn't getting enough fuel to start properly.
* Other sensor issues: Various other sensors, such as the Mass Airflow Sensor (MAF), can contribute to starting problems.
Never attempt to start a car by holding the gas pedal down unless explicitly instructed to do so by a qualified mechanic diagnosing a very specific problem. Doing so can lead to engine damage due to flooding or other issues. Instead, if your car won't start, take it to a mechanic to diagnose and repair the underlying cause.
